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本文通过实例介绍了求气相分解反应的反应物的离解度和平衡常数的方法。 对气相可逆分解反应来说,如果由题意能求出反应物和产物的平均分子量或分解前后的密度,就可求出反应物的离解度和可逆反应的平衡常数。例如,在298 K、101 325 Pa下,N_2O_4和NO_2混合物的密度为3.18g·L~(-1),求在该条件下N_2O_4的离解度和平衡常数。 相似文献
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青蒿素类药物的药理和毒理学研究 总被引：5，自引：0，他引：5
为了解青蒿素类药物的药理和毒理学研究进展,笔者查阅有关文献,综述了青蒿素类药物的药理与毒理学研究进展.研究结果表明:药动学研究显示此类药物吸收快、分布广、代谢与排泄快;青蒿素类药物除具有抗疟作用外,还有免疫调节、抗肿瘤、抗炎、抗血吸虫及其它寄生虫等作用;无严重的不良反应. 相似文献
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《绵阳师范学院学报》2017,(2)
采用密度泛函理论方法对气相中苯甲酰丙酮异构化为两种不同烯醇产物的反应机理进行了详细的探究,并对反应物、过渡态、产物的几何构型、键长的变化,布局电荷,振动频率,相对能进行了分析,发现反应物苯甲酰丙酮通过过渡态1生成产物烯醇1较通过过渡态2生成产物烯醇2更容易.此分析结果对进一步理解六元环酮-烯醇异构互变以及研究开发苯甲酰丙酮的新功能具有十分重要的指导意义. 相似文献
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马梦兰 《天津大学学报(英文版)》2000,6(2):162-165
开发了一种用于钢铁的化学热处理工艺——周期氮碳共渗 .该工艺是靠在封闭体积中由三嗪聚合物试剂所升华和分解的气相产物在工件表面形成涂层而处理工件的 .针对不同应用 ,对 F e-N-C系合金该工艺适用的温度范围很宽 ,既可低温氮碳共渗 ,也可超越低温做高温氮碳共渗 .该工艺还十分简便、经济易于控制 ,而且是无污染工艺 ,不像传统化学热处理工艺那样向大气排放有害气体 . 相似文献
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采用化学分析、红外光谱分析、差动热分析和红外谱图分析等方法初步分析了来自不同的患者的肾结石,结果是样品在常温下非常难溶于水和稀盐酸,在80℃时稍溶于稀盐酸;人体的必需元素铁、钾、钠和氨等离子都没有在化学分析中发现.差热分析在189～195℃左右有一个吸热峰,在425～495℃之间有两个放热峰,肾结石的主要成分是草酸钙,样品加热到550℃时就开始分解,分解后的主要产物是碳酸钙. 相似文献
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用TG-DTG(热重-微分热重)联用技术研究了氨茶碱片剂在氮气气氛中的热分解行为。首先运用普适法Kissinger和Ozawa法计算了氨茶碱片剂的表观活化能E和指前因子lnA,然后运用一般积分法Coats-Redfern法和Satava-Sestak法推测了主分解阶段的最佳热分解机理,推测出热分解机理为相边界反应,求出了热分解反应的表观活化能和指前因子。几种方法求得的表观活化能和指前因子的平均值分别为113.933KJ/mol,lnA为22.101(1/min).用malek法对所得结果进行了验证,进一步证明所得动力学参数和机理函数的正确性。 相似文献
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YONG Ke lan 《上海大学学报(英文版)》1999,3(4):321-324
１ Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｆｏｓｓｉｌｆｕｅｌｓａｒｅｔｈｅｓｏｌｉｄ,ｌｉｑｕｉｄａｎｄｇａｓｍｉｎｅｒａｌｓｔｈａｔｃｏｎｔａｉｎｃａｒｂｏｎａｎｄｈｙｄｒｏｇｅｎｅｌｅｍｅｎｔｓａｎｄｃａｎｂｅｕｓｅｄａｓｆｕｅｌ,ｉｎｃｌｕｄｉｎｇｃｏａｌ,ｐｅｔｒｏｌｅｕｍ,ｎａｔｕｒａｌｇａｓａｎｄｓｏｕｒｃｅｒｏｃｋ．Ｔｈｅｒｅａｒｅａｂｕｎｄａｎｔａｒｏｍａｔｉｃｈｙｄｒｏｃａｒｂｏｎｃｏｍｐｏｕｎｄｓｉｎｆｏｓｓｉｌｆｕｅｌｓ．Ｂｅｃａｕｓｅｏｆｉｔｓｇｒｅａｔｓｅｎｓｉｔｉｖｉｔｙｆｏｒ… 相似文献
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INTRODUCTIONTherearefewofquantitativethermalanalysis(TA)investigations (Mulokozi,1992 )ofthegoverningrelationsbetweentheparametersofsolidphasereactionkineticsandtheaveragedi ametersofultrafinecalciumcarbonateandtheeffectsoffineparticlesontheirsolidphasere… 相似文献
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Based on a systemic survey, the pyrolysis characteristics and apparent kinetics of the municipal solid waste （ MSW） under different conditions were researched using a special pyrolysis reactor, which could overcome the disadvantage of thermo-gravimetric analyzer. The thermal decomposition behaviour of MSW was investigated using thermo-gravimetric （ TG ） analysis at rates of 4.8,6.6,8.4, 12.0 and 13. 2 K/min. The pyrolysis characteristics of MSW were also studied in different function districts. The pyrolysis of MSW is a complex reaction process and three main stages are found according to the results. The first stage represents the degradation of cellulose and hemicellulose, with the maximum degradation rate occuring at 150℃ -200 ℃： the second stage represents dehydrochlorination and depolymerization of intermediate products and the differential thermogravimetric （ DTG ） curves have shoulder peaks at about 300℃： the third stage is the decomposition of the residual big molecular organic substance and lignin at 400 ℃- 600 ℃. Within the range of given experimental conditions, the results of non-linear fitting algorithm and experiment are in agreement with each other and the correlation coefficients are over0. 99. The kinetic characteristics are concerned with the material component and heating rate. The activation energy of reaction decreases with the increase of heating rate. 相似文献
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采用阴离子直接交换法、酸性和碱性条件下原位一步合成法分别制备了Mg2Al-己二酸根插层水滑石,用XRD、IR对合成的样品进行了组成和结构表征,DTA结合不同温度下焙烧样品的XRD和IR分析研究了样品的热分解过程.结果表明,各种方法均能合成出相应的插层水滑石层柱材料,但相比之下,原位一步合成法不仅步骤简便,而且合成的样品具有更好的结晶性和层有序性.DTA研究表明,有机阴离子插层水滑石样品的热分解经历了脱除表面和层间吸附水、脱羟基(层结构破坏)、有机阴离子的燃烧分解以及无定形氧化物的晶化等一系列过程. 相似文献
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IN REEENT YEARS，MUEH ATTENTION HAS BEEN PAID TO DIARYL一SUBSTITUTED HETEROEYELES THAT ARE ASSOEIATED WITH HIGH BIOLOGIEAL AETIVITIES AS SELEETIVE COX一2 INHIBI- TORS[L〕AND ANRITUMOR AGENTS[21.A NEW EOM卯UND， NAMELY4一{5一[3，4一DIMETHYL一5一(3，4，5一T 相似文献
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Vacuum pyrolysis was employed to dispose scrap brominated epoxy printed circuit boards (PCBs). Pyrolysis characteristics of waste PCBs under normal pressure and vacuum were investigated in this paper. A detailed study on the analysis of the elemental composition of PCBs and the pyrolysis products was performed. The thermal decomposition kinetics was measured by a thermogravimetric (TG) analyzer. The activation energy of pyrolysis under nitrogen atmosphere and vacuum were 193 kJ/mol to 206 kJ/mol and 145 kJ/mol to 165 kJ/mol, respectively. The composition of materials was analyzed by elemental analyzer. The pyrolysis products were analyzed by GC (gas chromatograph), GC-MS (chromatography and mass spectrometry) and FT-IR (Fourier transform infrared spectroscopy). Vacuum helped to increase the yield of pyrolysis oil. The liquid yield of PCBs pyrolysis at 15 kPa and normal pressure were 31.3? and 23.5?, respectively. The main components in pyrolysis oils were phenol, isopropyl-phenol, and their brominated substitution. 相似文献
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Comparative study on the pyrolysis behaviors of corn stalk and pine sawdust using TG-MS 总被引：1，自引：0，他引：1
The pyrolysis behaviors of corn stalk（CS） and pine sawdust（PS） were investigated with thermogravimetry-mass spectroscopy（TG-MS）.The peak temperature of PS was higher and the main decomposition region shifted to higher temperature compared with CS,which implied that the hemicellulose and cellulose of PS were more thermally stable than those of CS.However,the hemicellulose and cellulose of PS were more easily decomposed into gaseous products than those of CS during pyrolysis.The pyrolysis process of biomass can be described by a two-step independent first-order kinetic model.This fundamental study provides a basic insight into the biomass pyrolysis,which is beneficial for understanding the pyrolysis mechanism of biomass and developing an advanced thermal process for effective utilization of biomass. 相似文献
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采用热重法（TG）测定了2-（4-甲氧羰基苯基）-5-氨基-6-羟基苯并嗯唑（MAB）的热分解过程,测定了MAB及其在热分解过程中不同阶段产物的红外光谱,运用量子化学GAMESS软件计算了MAB分子的键级,推断了MAB的热分解机理,结果表明MAB的热分解过程是一个五阶段过程,起始步骤是甲基酯的分解、根据不同升温速率下的热重曲线计算得到MAB第一阶段热分解反应的表观活化能Eα=157．1kJ·mol^-1和指前因子A=3．715×10^13。 相似文献